tone-tentative and polite

I think the tone of the message below is quite tentative and polite and I don't think we often write a message to teachers like this. I rewrote the message, and could you tell me which tone is often used in authentic samples written in real-life contexts, the first one or the second one? And could you create the tone of the sencond one to make it more authentic? Thank you!
1. Dear Professor Stone,
I have called several times to ask for a favor but have been unable to find you at your office. I was wondering if I could borrow your DVD player--to watch the movie Skokie you told us about in class. If it is possible, will you please contact me at the EI Camino Hall in Room 402? Thanks.
Sara Ho
2. Dear Prof. Stone,
I called you several times but cannot find you at your office. I would like to borrow your DVD player--to watch the movie Skokie you told us about in class. Could you contact me ath the EI Camino Hall in Room 402? Thanks.
Sara Ho